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authorLinus Torvalds <torvalds@linux-foundation.org>2018-12-01 05:32:33 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2018-12-01 05:32:33 +0300
commitfd3b3e0ec59db813d3ff665e158b1390ecdcfd14 (patch)
tree412e14f38f516352710da2518e15f4416e116e97 /fs
parent38c7b224ce22c25fed04007839edf974bd13439d (diff)
parent31ffa563833576bd49a8bf53120568312755e6e2 (diff)
downloadlinux-fd3b3e0ec59db813d3ff665e158b1390ecdcfd14.tar.xz
Merge tag 'fscache-fixes-20181130' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs
Pull fscache and cachefiles fixes from David Howells: "Misc fixes: - Fix an assertion failure at fs/cachefiles/xattr.c:138 caused by a race between a cache object lookup failing and someone attempting to reenable that object, thereby triggering an update of the object's attributes. - Fix an assertion failure at fs/fscache/operation.c:449 caused by a split atomic subtract and atomic read that allows a race to happen. - Fix a leak of backing pages when simultaneously reading the same page from the same object from two or more threads. - Fix a hang due to a race between a cache object being discarded and the corresponding cookie being reenabled. There are also some minor cleanups: - Cast an enum value to a different enum type to prevent clang from generating a warning. This shouldn't cause any sort of change in the emitted code. - Use ktime_get_real_seconds() instead of get_seconds(). This is just used to uniquify a filename for an object to be placed in the graveyard. Objects placed there are deleted by cachfilesd in userspace immediately thereafter. - Remove an initialised, but otherwise unused variable. This should have been entirely optimised away anyway" * tag 'fscache-fixes-20181130' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs: fscache, cachefiles: remove redundant variable 'cache' cachefiles: avoid deprecated get_seconds() cachefiles: Explicitly cast enumerated type in put_object fscache: fix race between enablement and dropping of object cachefiles: Fix page leak in cachefiles_read_backing_file while vmscan is active fscache: Fix race in fscache_op_complete() due to split atomic_sub & read cachefiles: Fix an assertion failure when trying to update a failed object
Diffstat (limited to 'fs')
-rw-r--r--fs/cachefiles/namei.c8
-rw-r--r--fs/cachefiles/rdwr.c9
-rw-r--r--fs/cachefiles/xattr.c3
-rw-r--r--fs/fscache/object.c3
4 files changed, 16 insertions, 7 deletions
diff --git a/fs/cachefiles/namei.c b/fs/cachefiles/namei.c
index 95983c744164..1645fcfd9691 100644
--- a/fs/cachefiles/namei.c
+++ b/fs/cachefiles/namei.c
@@ -244,11 +244,13 @@ wait_for_old_object:
ASSERT(!test_bit(CACHEFILES_OBJECT_ACTIVE, &xobject->flags));
- cache->cache.ops->put_object(&xobject->fscache, cachefiles_obj_put_wait_retry);
+ cache->cache.ops->put_object(&xobject->fscache,
+ (enum fscache_obj_ref_trace)cachefiles_obj_put_wait_retry);
goto try_again;
requeue:
- cache->cache.ops->put_object(&xobject->fscache, cachefiles_obj_put_wait_timeo);
+ cache->cache.ops->put_object(&xobject->fscache,
+ (enum fscache_obj_ref_trace)cachefiles_obj_put_wait_timeo);
_leave(" = -ETIMEDOUT");
return -ETIMEDOUT;
}
@@ -336,7 +338,7 @@ static int cachefiles_bury_object(struct cachefiles_cache *cache,
try_again:
/* first step is to make up a grave dentry in the graveyard */
sprintf(nbuffer, "%08x%08x",
- (uint32_t) get_seconds(),
+ (uint32_t) ktime_get_real_seconds(),
(uint32_t) atomic_inc_return(&cache->gravecounter));
/* do the multiway lock magic */
diff --git a/fs/cachefiles/rdwr.c b/fs/cachefiles/rdwr.c
index 40f7595aad10..8a577409d030 100644
--- a/fs/cachefiles/rdwr.c
+++ b/fs/cachefiles/rdwr.c
@@ -535,7 +535,10 @@ static int cachefiles_read_backing_file(struct cachefiles_object *object,
netpage->index, cachefiles_gfp);
if (ret < 0) {
if (ret == -EEXIST) {
+ put_page(backpage);
+ backpage = NULL;
put_page(netpage);
+ netpage = NULL;
fscache_retrieval_complete(op, 1);
continue;
}
@@ -608,7 +611,10 @@ static int cachefiles_read_backing_file(struct cachefiles_object *object,
netpage->index, cachefiles_gfp);
if (ret < 0) {
if (ret == -EEXIST) {
+ put_page(backpage);
+ backpage = NULL;
put_page(netpage);
+ netpage = NULL;
fscache_retrieval_complete(op, 1);
continue;
}
@@ -962,11 +968,8 @@ void cachefiles_uncache_page(struct fscache_object *_object, struct page *page)
__releases(&object->fscache.cookie->lock)
{
struct cachefiles_object *object;
- struct cachefiles_cache *cache;
object = container_of(_object, struct cachefiles_object, fscache);
- cache = container_of(object->fscache.cache,
- struct cachefiles_cache, cache);
_enter("%p,{%lu}", object, page->index);
diff --git a/fs/cachefiles/xattr.c b/fs/cachefiles/xattr.c
index 0a29a00aed2e..511e6c68156a 100644
--- a/fs/cachefiles/xattr.c
+++ b/fs/cachefiles/xattr.c
@@ -135,7 +135,8 @@ int cachefiles_update_object_xattr(struct cachefiles_object *object,
struct dentry *dentry = object->dentry;
int ret;
- ASSERT(dentry);
+ if (!dentry)
+ return -ESTALE;
_enter("%p,#%d", object, auxdata->len);
diff --git a/fs/fscache/object.c b/fs/fscache/object.c
index 9edc920f651f..6d9cb1719de5 100644
--- a/fs/fscache/object.c
+++ b/fs/fscache/object.c
@@ -730,6 +730,9 @@ static const struct fscache_state *fscache_drop_object(struct fscache_object *ob
if (awaken)
wake_up_bit(&cookie->flags, FSCACHE_COOKIE_INVALIDATING);
+ if (test_and_clear_bit(FSCACHE_COOKIE_LOOKING_UP, &cookie->flags))
+ wake_up_bit(&cookie->flags, FSCACHE_COOKIE_LOOKING_UP);
+
/* Prevent a race with our last child, which has to signal EV_CLEARED
* before dropping our spinlock.